NO MORE SEA-SICKNESS.

New Zealand Herald, Volume XLVIII, Issue 14691, 27 May 1911, Page 2 (Supplement)

NO MORE SEA-SICKNESS.

SHIPS THAT CANNOT ROLL.

TANKS THAT COUNTERACT WAVES.

Even the waves of the sea can now be conquered by modern science. Bad sailors will rejoice to hear that experts in naval construction have devised a plan which will minimise, if not, perhaps, stop altogether, the rolling of a ship at sea.

Sir Phillip Watts, the Director of Naval Construction since 1901, who was present at the last day's sitting of tho spring meeting of the Institute of Naval Architects, when Dr. H. Frahm, a German engineer, read a paper on recent experiments with anti-rolling tanks, states that the idea of anti-rolling tanks, filled with water, had been carried out in the old ironclad Inflexible. Tho tanks decribed by Dr. Frahm are erected on each side of tho vessel, and are connected by an extremely large pipe or channel, so that tho water in them can llow from one tank to tho other. Sir Phillip Watts described the plan or device as a " ship that carries her own waves"—and these waves in tho tank counteract, to a great extent, the real waves of the sea. " A ship at sea," said Sir Phillip, " synchronises in her rolling with the waves. She does not hurry or delay in her swing, but moves just as the waves force her to. Her movement is what is known as ' coperiodic.' " But when a vessel is fitted with ' antirolling tanks,' and she goes to starboard, some ninety tons of water in her tanks goes over to starboard, too. This weight of water delays her from coming back on tho rhythm of the waves, and really acts as a wave working in the opposite direction.

" Consequently, tho regular swing of tho waves is broken, and the ship, by virtue of her own self-carried waves, is able to resist,. at least to a large extent, the power of tho waves of the sea.

" The idea, however, is not new, I myself designed two ' anti-rolling tanks ' for the old battleship Inflexible in 1883, but, owing to the difficulty of finding room for them, only one was constructed. "This tank, owing to want of space, was of the same depth right across the ship, but even then it reduced the rolling by some 25 per cent." " I do not think that these tanks could be fitted with oil-fuel, because it is difficult to build tanks which are oil-tight." Horr Frahm, in his lecturo on his antirolling tanks, stated that experiments on two large trans-Atlantic passenger steamers, the Ypiranga and Corcovado, vessels of 14,100 tons loaded displacement, which, though new and of excellent constructiqp, were said to bo bad rollers, had been very successful. Even under the worst conditions tho tanks had a very favourable influence, and when. during experiments, they were temporarily discontinued, the passengers urged to have them put into use again. Anti-rolling tanks would doubtless prove of the greatest importance to men-o'-war. A steady gun-platform was almost indispensable to the gunner, and ho was, he added, about to make experiments on another form of anti-rolling device, which was especially suited to men-o'-war. Sir Phillip Watts described the experiments on the old Inflexible, saying the waterchamber acted satisfactorily. The water, however, made a great noise. Water, too, added Sir John Thornycroft, required an appreciable amount of space. It would be an advantage if they could use something heavier than water. Of course, if mercury were not so expensive, the tanks could be got in a very small space. If they were hampered for space, the gyroscope might overcome the difficulty.